1. Field of the Invention
The invention relates to handlebar-mounted electronic sensor assemblies for a motorcycle with which to detect an operator's request for a given throttle angle and/or torque output from the motorcycle's engine, the sensor output signal thereafter being used by an engine control processor to thereby control engine operation.
2. Background Art
The prior art teaches electronic throttle control (ETC) systems for motor vehicles in which an operator's request for a desired throttle angle or torque output is detected by at least one electronic sensor to obtain a throttle request signal that is thereafter used by an engine control module in selecting a suitable engine operating condition, for example, through adjustment of such engine operating parameters as engine air-fuel ratio (either through control of air mass flow, of metered fuel, or both), ignition timing or “spark,” EGR, and valve timing, among others. Thus, for example, U.S. Pat. No. 6,276,230 teaches a handlebar throttle controller for a motorcycle in which an angle sensor generates an output voltage generally proportional to the extent to which an operator has angularly displaced a grip relative to the handlebar. A return spring biases the grip towards a first angular position against an idle stop to ensure that the request signal returns to an idle request upon release by the operator of the grip.
Unfortunately, the operation and feel of such spring-biased handlebar throttle controllers remains significantly different from mechanical throttle linkages. With mechanical throttle linkages using a sheathed cable, torque defines a hysteresis loop characterized by an increased resistance to relative angular movement of the grip as the operator requests an increased engine output, and increased hysteresis as angular movement increases. This torque displacement characteristic is created at least in part due to the frictional interaction of the control cable, its enveloping sheath, the throttle return spring and linkage geometry.
Accordingly, what is needed is a handlebar throttle controller that provides a more-realistic throttle “feel” than is provided by such known handlebar throttle controllers providing the operator with good control of the engine.